Some Nokia N8 smartphones are turning themselves off or refusing to turn on after charging. Nokia has identified a manufacturing problem and has promised to replace the small number of affected phones it said in a blog post on Thursday.

N8 owners have been complaining that their N8 turns itself off unexpectedly or doesn't power up as it is should, according to Niklas Savander, executive vice president and general manager of Nokia's Markets unit.

The issue is covered by the standard warranty, and affected N8 owners should turn to Nokia's care centers, Savander said.

The problem is connected to the way Nokia assembles the phones' main circuit board containing basic electronics and radio-frequency components, according to Savander.

To address the issue Nokia has taken measures across the product line, Savander said.

Savander wouldn't say how many phones have been affected by the issue, only saying that it is a "small" number. However, for affected customers it is a significant issue and something that needs to be fixed, he said.

The N8 will be an important product for Nokia during the holiday shopping season, and issues like this can have a negative impact if they aren't dealt with in a swift manner, according to Roberta Cozza, principal analyst at Gartner. Nokia has to be careful, she said.